Prefabricated modular building units

ABSTRACT

A folding beam system  16  for use in the assembly of pre-fabricated modular building units having beam members  20, 22  for supporting the floor and ceiling structures of the modular unit, said beam members being adjacent to each other when the modular units are arranged in a vertical stack, an open web structure  24  pivotally associated with one of the beam members  20  to allow the web structure  24  to be folded from a stored position, to an operative position in which the web structure is connected to the other beam member  22  of a vertically adjacent unit to form a structural truss  16  between the adjacent units, and means  28, 29  for locking the web structure to the other beam  22  in the operative position.

This invention relates to improvements in prefabricated modular units for use in constructing buildings of many different types, including commercial, retail, residential and institutional. This invention also relates to structural members for use in the construction of such units.

Prefabricated modular units have been used with some success in the building industry. Since such units are prefabricated, the on-site building times may be significantly reduced.

Examples of prefabricated modular units are to be found in the patent literature, for example, U.S. Pat. No. 3,514,910 and U.S. Pat. No. 3,500,595. Such units are usually characterised by the use of substantial reinforced concrete structures or complex engineering details which increase the cost of the units and their transport from the unit construction site to the building site. The interconnection of units in a vertical stack of units is similarly complex and costly.

The patent literature also has examples of folding beams for use in prefabricated units, for example U.S. Pat. No. 4,546,591 and Australian Patent No. 2004202965.

It is an object of the present invention to provide a less complex means for rigidly interconnecting stacked units which improves the structural strength of the combined units.

The invention provides a folding beam system for use in the assembly of pre-fabricated modular building units having beam members for supporting the floor and ceiling structures of the modular unit, said beam members being adjacent to each other when the modular units are arranged in a vertical stack, an open web structure pivotally associated with one of the beam members to allow the web structure to be folded from a stored position, out of the central vertical plane of the beam, which reduces the vertical height of the unit for transportation, to an operative position in which the web structure is connected to the other beam member of a vertically adjacent unit to form a structural truss between the adjacent units, and means for locking the web structure to the other beam in the operative position.

In one form, web structures are pivotally associated with either side of said one of the beam members, and in another form a single web structure is pivotally associated with said beam member at or near a central vertical plane of the beam member of the beam.

The web structure may be pivotally mounted on one of the beam members and have an opening formed to engage a support element secured to the other beam, locking means including a locking pin engaging means associated with the other beam.

In one form, the locking pin engages cleat plates on either side of the support block positioned to locate the web structure longitudinally of the beam.

In another form, the invention provides a pre-fabricated modular building unit for use with like modular units in the construction of buildings, comprising a cubic structure having column elements at each corner and spaced along each side if required, to provide structural strength, frame members connecting the column elements for supporting floor, ceiling and wall panels to provide structural rigidity, said unit being configured to co-operate with like units so that the column elements form the columns of the building structure, said frame members including beam members for supporting floor and ceiling structures of the modular unit, a folding beam system including an open webbed structure pivotally associated with one of the beam members to allow the web structure to be folded from a stored position, out of the central vertical plane of the beam member, to an operative position connected to the other beam member of a vertically adjacent modular unit, to rigidly interconnect the modular units and define a structural truss interconnecting the units, and means for locking the web structure to the other beam in the operative position.

In one form, the column elements along one side of the modular unit includes removable column members which remain in position while the unit is transported and installed with like units, said column members being removable when the folding beam system of vertically adjacent units are deployed to the operative position and the beam members of the adjacent units are interconnected to span horizontally adjacent units.

The beam members of adjacent units may be interconnected by gusset plates including compression blocks which are received between adjacent column elements.

In one form, the column elements of horizontally adjacent modular units are interconnected by interlocking brackets which thereby rigidly interconnect the adjacent modular units.

The removable column members include tubular members which are adjustable in length and which contain tension rods which are secured to opposed supports for the removable columns, the tension rods being removable to allow disassembly of the removable columns when the folding beam systems have been deployed to the operative position and the beam members of adjacent units have been inter-connected to span horizontally adjacent units.

In order that the invention may be more readily understood, an embodiment will now be described with reference to the accompanying drawings in which:

FIG. 1 is a schematic perspective view of prefabricated modular building units embodying the invention in a four unit assembly;

FIGS. 2 and 3 illustrate one folding beam system embodying the invention;

FIG. 4 illustrates a light weight folding beam system embodying the invention;

FIG. 5 is a sectional view of a gusset plate arrangement for interconnecting the folding beams systems illustrated in FIG. 1;

FIG. 6 illustrates the column to column interface of the modules;

FIGS. 7 to 11 illustrate interlocking bracket arrangements for interconnecting adjacent columns, and

FIG. 12 illustrates one form of removable column arrangement for use in the modular construction illustrated in FIG. 1.

Referring firstly to FIG. 1 of the drawings, this figure schematically illustrates a structure comprising four prefabricated modular units 1 embodying the invention. Each unit will usually include corner columns 2 of hollow steel section, and intermediate columns 4 and 6 along each side, but in the arrangement shown, the corner columns and the intermediate columns along adjacent sides of the modular units 1 are replaced by temporary or removable columns 8, 9, 10 and 11.

The steel framed modular units are essentially “laid” to form the primary modular “building blocks” for the building envelope. The units interconnect with each other to form a rigid structure. The designs within this system will be able to accommodate reinforced concrete floor systems as well as light weight flooring systems. The modular units can form a building consisting wholly of such units or can be integrated with other forms of construction such as the central cores of multi-storey buildings comprising lift shafts, services shafts, stairwells and basements.

To meet the requirements of the Building Code of Australia, and the other building codes/regulations of other countries, it is necessary to design the supporting columns 1 so that they are capable of achieving a prescribed fire resistance level, depending on the type of building and its height. To meet the prescribed fire resistance level, each hollow section column 1 is filled with concrete in any suitable manner. The compressive strength of the concrete mix in the column 1 varies according to the structural design variables of the column and the fire resistance level required to be obtained.

The columns 1, 4 and 6 are interconnected by frame members 12 and the upper and lower supports 13 for the removable columns 8 to 11 are interconnected by removable frame members 15 which remain in place with the removable columns during transport and assembly of the structure illustrated.

The frame members 12 are connected by diagonal braces 14, and folding beam systems 16, described further below, across each module and suitably interconnected by gusset plates 17 to span the pairs of adjacent modules as illustrated to support the floor 18 and ceiling (not shown) structures. FIG. 5 illustrates one suitable form that the gusset plates 17 may take, and in this form, compression blocks 19 are positioned between adjacent columns or supports for the temporary columns as clearly illustrated in FIG. 5.

Referring to FIGS. 2 and 3, a first embodiment of the folding beam system 16, suitable for relatively heavy floor loads, is illustrated. The folding beam system 16 includes a top cord 20 in the form of a floor supporting beam, and a ceiling supporting beam bottom cord 22. An open web structure 24 is attached to hinge mechanisms 26 secured to the top cord 20 on either side (only one side shown in FIG. 2 for clarity) and the web structures 24 are thereby able to hinge from a stored position illustrated in FIG. 3 to an operative position in which support blocks 23 engage apertures 25 to allow a locking pin 28 to engage cleat plates 29 as illustrated in FIG. 3. The cleat plates 29 serve to locate the web structure 24 longitudinally of the beam 22. In this way, the adjacent floor supporting beams and the ceiling supporting beams are locked together to define a structural truss to thereby namely interconnect the modular units increase the strength of the structure. FIG. 4 illustrates a light weight version of the folding beam system in which an upper cord 30 for supporting light weight flooring and lower cord 32 for supporting a ceiling structure are connected by an open web structure 34 pivoted in the manner illustrated in FIG. 4 to the upper cord 30 in its central vertical plane and locked to the lower cord 32 by locking pins (not shown).

Turning now to FIG. 6 of the drawings, the end to end connections of the load bearing columns 1 include a central guiding dowel 40 grouted into the lower column and engaging an opening in end bearings spreader plates 42 and hard rubber pads 44 positioned between the spreader plates 42.

As schematically depicted in FIG. 6, interlocking brackets 46 hold adjacent columns together at each end of the columns. Suitable interlocking bracket arrangements are illustrated in FIGS. 7 to 11. In the arrangement illustrated in FIG. 7, a slotted sleeve bracket 50 and support plate 52 are welded to a column 1 while a T-shaped interlocking bracket 54 is welded to another column 1 (shown in broken outline) so that when the interlocking bracket engages the sleeve bracket a locking pin 56 engages the sleeve bracket to hold the assembly in interlocking engagement, as more clearly illustrated in FIG. 8.

In the arrangement illustrated in FIG. 9, interlocking brackets 58 engage sleeve brackets 59 on the columns 1 and the interlocking brackets 58 are bolted together.

In the arrangement of FIG. 10, designed for earth quake regions, reinforced angular brackets 60 are designed to be bolted together in face to face engagement.

In the arrangement of FIG. 11, designed for attachment to the outer sides of the columns 1, plates 62 have hinged flaps 64 which are bolted together as evident from FIG. 11.

It will be appreciated from the above that the interlocking bracket systems illustrated require that the construction of the pre-fabricated modular units should be in horizontal layers for the horizontal length of the building before the next layer is installed. It is also required that the interlocking brackets should be reversed in orientation on consecutive layers of the modular units to enable suitable interlocking as the units are lowered into position. Other locking bracket arrangements may be used with equal recess.

Referring now to FIG. 12 of the drawings, the removable columns 8 are illustrated in greater detail. The columns 8 are hollow steel tube elements 80 with end bearing plates 82 and packing members 84 of timber which are provided at each end to protect the floor and ceiling finishes. Tension rods 86 passes through the tube element 80 and associated threaded connection tubes 88 connect the tension rods 86 to threaded anchor bolts 90 secured within a concrete filled base member 91 for each column 8 as clearly illustrated in FIG. 12.

The removable columns 8 further include an adjustable threaded sleeve 92 engaging threaded portions of the tube elements 80 to allow adjustment of the column length to support the required loads. Interlocking bracket arrangements 94, of any suitable type, are positioned between the base units 91 and the corresponding ceiling units 93, through which the tension rods 86 pass terminating in lifting lugs 95 which allow the tension rods to be unscrewed and removed from the base units.

Once the folding beam systems 16 are fully operational, the removable columns 8 can be removed. Removal is achieved by unthreading the tension rod 86 from its connection tube 88 and the tension rod is removed using the lifting lugs 95. The column 8 is then removed by releasing the compression force by turning the adjustment sleeve 92 allowing the column to become shorter to facilitate removal. Once the columns 8 are removed, it will be appreciated that the region between the adjacent modular units will be column free providing spatial continuity between the adjacent modular units, allowing significant design flexibility not previously available in prefabricated modular unit constructions.

The folding beam system may also be used in reverse where the hinge mechanism is located on the bottom cord (ceiling beam/joist) and the open web is folded up into the vertical position and connected to the top chord. The reverse position can be beneficial where the materials for the floor loads are heavy for the upper modular units and deflection of the floor beam (top chord) may compromise the efficiency of the hinge operation.

Access panel/openings (not shown) in the plasterboard ceiling panels are required for the purpose of accessing the ceiling space to enable the web connection via the islet loop/socket arrangement and the insertion of the locking rod.

Various types of floor systems can be associated with the folding beam system. These include standard reinforced concrete floor slabs to light weight “drop in” floor panels. Where reinforced concrete slabs are proposed, additional beam depth can be achieved by integrating the slab with the beam component for structural composite action. This is achieved by the introduction of shear connection pins at the top of the beam flange. The “drop-in” floor panels are arranged such that they sit within the depth of the beam configuration.

The framing arrangements illustrated in FIG. 1, and particularly the columns and associated in plane diagonal bracing define deep trusses that provide significant advantages in spanning over spaces below and allow for cantilevering effects in the articulation of the buildings construction such as the external facade and balcony arrangements.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates. 

1. A folding beam system for use in the assembly of pre-fabricated modular building units having beam members for supporting the floor and ceiling structures of the modular unit, said beam members being adjacent to each other when the modular units are arranged in a vertical stack, an open web structure pivotally associated with one of the beam members to allow the web structure to be folded from a stored position, out of the central vertical plane of the beam, which reduces the vertical height of the unit for transportation, to an operative position in which the web structure is connected to the other beam member of a vertically adjacent unit to form a structural truss between the adjacent units, and means for locking the web structure to the other beam in the operative position.
 2. The folding beam of claim 1, wherein a said web structure is pivotally associated with either side of said one of the beam members.
 3. The folding beam of claim 1, wherein a single said web structure is pivotally associated with said one of said beam members at or near a central vertical plane of the beam member.
 4. The folding beam of claim 1, wherein the or each web structure is pivotally mounted on one of the beam members and have an opening formed to engage a support element secured to the other beam member, locking means including a locking pin engaging means associated with the other beam member.
 5. The folding beam of claim 4, wherein the locking pin engages cleat plates on either side of the support element positioned to locate the web structure longitudinally of the beam member.
 6. A pre-fabricated modular building unit for use with like modular units in the construction of buildings, comprising a cubic structure having column elements at each corner and spaced along each side if required, to provide structural strength, frame members connecting the column elements for supporting floor, ceiling and wall panels to provide structural rigidity, said unit being configured to co-operate with like units so that the column elements form the columns of the building structure, said frame members including beam members for supporting floor and ceiling structures of the modular unit, a folding beam system including an open webbed structure pivotally associated with one of the beam members to allow the web structure to be folded from a stored position, out of the central vertical plane of the beam member, to an operative position connected to the other beam member of a vertically adjacent modular unit, to rigidly interconnect the modular units and define a structural truss interconnecting the units, and means for locking the web structure to the other beam in the operative position.
 7. The building unit of claim 6, wherein the column elements along one side of the modular unit includes removable column members which remain in position while the unit is transported and installed with like units, said column members being removable when the folding beam system of vertically adjacent units are deployed to the operative position and the beam members of the adjacent units are interconnected to span horizontally adjacent units.
 8. The building unit of claim 7, wherein the beam members of adjacent units may be interconnected by gusset plates including compression blocks which are received between adjacent column elements.
 9. The building unit of claim 6, wherein the column elements of horizontally adjacent modular units are interconnected by interlocking brackets which thereby rigidly interconnect the adjacent modular units.
 10. The building unit of claim 7, wherein the removable column members include tubular members which are adjustable in length and which contain tension rods which are secured to opposed supports for the removable columns, the tension rods being removable to allow disassembly of the removable columns when the folding beam systems have been deployed to the operative position and the beam members of adjacent units have been inter-connected to span horizontally adjacent units. 